• Imaging Science in Dentistry
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• 제53권4호
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• pp.325-333
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• 2023

Purpose: The objective of this study was to evaluate and compare the accuracy and image quality of root surface area (RSA) measurements obtained with various cone-beam computed tomography (CBCT) protocols, relative to the gold standard of micro-computed tomography (CT), in an in vitro setting. Materials and Methods: Four dry human skulls were scanned using 8 different protocols, with voxel sizes of 0.15 mm, 0.3 mm, and 0.4 mm. Three-dimensional models of the selected teeth were constructed using CBCT and microCT protocols, and the RSA was automatically measured by the image-processing software. The absolute difference in the percentage of the RSA(%ΔRSA) was calculated and compared across the 8 CBCT protocols using repeatedmeasures analysis of variance. Finally, image quality scores of the RSA measurements were computed and reported in terms of percent distribution. Results: No significant differences were observed in the %ΔRSA across the 8 protocols (P>0.05). The deviation in %ΔRSA ranged from 1.51% to 4.30%, with an increase corresponding to voxel size. As the voxel size increased, the image quality deteriorated. This decline in quality was particularly noticeable at the apical level of the root, where the distribution of poorer scores was most concentrated. Conclusion: Relative to CBCT protocols with voxel sizes of 0.15mm and 0.3mm, the protocols with a voxel size of 0.4 mm demonstrated inferior image quality at the apical levels. In spite of this, no significant discrepancies were observed in RSA measurements across the different CBCT protocols.

• Childhood Kidney Diseases
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• 제19권2호
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• pp.56-64
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• 2015

To revise the clinical guideline for childhood urinary tract infections (UTIs) of the Korean Society of Pediatric Nephrology (2007), the recently updated guidelines and new data were reviewed. The major revisions are as follows. In diagnosis, the criterion for a positive culture of the catheterized or suprapubic aspirated urine is reduced to 50,000 colony forming uits (CFUs)/mL from 100,000 CFU/mL. Diagnosis is more confirmatory if the urinalysis is abnormal. In treating febrile UTI and pyelonephritis, oral antibiotics is considered to be as effective as parenteral antibiotics. In urologic imaging studies, the traditional aggressive approach to find primary vesicoureteral reflux (VUR) and renal scar is shifted to the targeted restrictive approach. A voiding cystourethrography is not routinely recommended and is indicated only in atypical or complex clinical conditions, abnormal ultrasonography and recurrent UTIs. $^{99m}Tc$-DMSA renal scan is valuable in diagnosing pyelonephritis in children with negative culture or normal RBUS. Although it is not routinely recommended, normal scan can safely avoid VCUG. In prevention, a more natural approach is preferred. Antimicrobial prophylaxis is not supported any more even in children with VUR. Topical steroid (2-4 weeks) to non-retractile physiologic phimosis or labial adhesion is a reasonable first-line treatment. Urogenital hygiene is important and must be adequately performed. Breast milk, probiotics and cranberries are dietary factors to prevent UTIs. Voiding dysfunction and constipation should be properly treated and prevented by initiating toilet training at an appropriate age (18-24 months). The follow-up urine test on subsequent unexplained febrile illness is strongly recommended. Changes of this revision is not exclusive and appropriate variation still may be accepted.

• Nuclear Engineering and Technology
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• 제38권3호
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• pp.239-250
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• 2006

Computational anthropomorphic phantoms are computer models of human anatomy used in the calculation of radiation dose distribution in the human body upon exposure to a radiation source. Depending on the manner to represent human anatomy, they are categorized into two classes: stylized and tomographic phantoms. Stylized phantoms, which have mainly been developed at the Oak Ridge National Laboratory (ORNL), describe human anatomy by using simple mathematical equations of analytical geometry. Several improved stylized phantoms such as male and female adults, pediatric series, and enhanced organ models have been developed following the first hermaphrodite adult stylized phantom, Medical Internal Radiation Dose (MIRD)-5 phantom. Although stylized phantoms have significantly contributed to dosimetry calculation, they provide only approximations of the true anatomical features of the human body and the resulting organ dose distribution. An alternative class of computational phantom, the tomographic phantom, is based upon three-dimensional imaging techniques such as magnetic resonance (MR) imaging and computed tomography (CT). The tomographic phantoms represent the human anatomy with a large number of voxels that are assigned tissue type and organ identity. To date, a total of around 30 tomographic phantoms including male and female adults, pediatric phantoms, and even a pregnant female, have been developed and utilized for realistic radiation dosimetry calculation. They are based on MRI/CT images or sectional color photos from patients, volunteers or cadavers. Several investigators have compared tomographic phantoms with stylized phantoms, and demonstrated the superiority of tomographic phantoms in terms of realistic anatomy and dosimetry calculation. This paper summarizes the history and current status of both stylized and tomographic phantoms, including Korean computational phantoms. Advantages, limitations, and future prospects are also discussed.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제25권2호
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• pp.147-162
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• 2022

Purpose: To design a prospective study on endovascular closure of congenital portosystemic shunts. The primary endpoint was to assess the safety of endovascular closure. The secondary endpoint was to evaluate the clinical, analytical and imaging outcomes of treatment. Methods: Fifteen patients (age range: 2 days to 21 years; 10 male) were referred to our center due to congenital portosystemic shunts. The following data were collected prior to treatment: age, sex, medical history, clinical and analytical data, urine trimethylaminuria, abdominal-US, and body-CT. The following data were collected at the time of intervention: anatomical and hemodynamic characteristics of the shunts, device used, and closure success. The following data were collected at various post-intervention time points: during hospital stay (to confirm shunt closure and detect complications) and at one year after (for clinical, analytical, and imaging purposes). Results: The treatment was successful in 12 participants, migration of the device was observed in two, while acute splanchnic thrombosis was observed in one. Off-label devices were used in attempting to close the side-to-side shunts, and success was achieved using Amplatzer™ Ductus-Occluder and Amplatzer™ Muscular-Vascular-Septal-Defect-Occluder. The main changes were: increased prothrombin activity (p=0.043); decreased AST, ALT, GGT, and bilirubin (p=0.007, p=0.056, p=0.036, p=0.013); thrombocytopenia resolution (p=0.131); expansion of portal veins (p=0.005); normalization of Doppler portal flow (100%); regression of liver nodules (p=0.001); ammonia normalization (p=0.003); and disappearance of trimethylaminuria (p=0.285). Conclusion: Endovascular closure is effective. Our results support the indication of endovascular closure for side-to-side shunts and for cases of congenital absence of portal vein.

• Archives of Plastic Surgery
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• 제50권1호
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• pp.30-36
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• 2023

Background Most children with facial lacerations require sedation for primary sutures. However, sedation guidelines for invasive treatment are lacking. This study evaluated the current status of the sedation methods used for pediatric facial laceration repair in Korea. Methods We surveyed one resident in each included plastic surgery training hospital using face-to-face interviews or e-mail correspondence. The health care center types (secondary or tertiary hospitals), sedation drug types, usage, and dosage, procedure sequence, monitoring methods, drug effects, adverse events, and operator and guardian satisfaction were investigated. Results We included 45/67 hospitals (67%) that used a single drug, ketamine in 31 hospitals and chloral hydrate in 14 hospitals. All health care center used similar sedatives. The most used drug administered was 5 mg/kg intramuscular ketamine (10 hospitals; 32%). The most common chloral hydrate administration approach was oral 50 mg/kg (seven hospitals; 50%). Twenty-two hospitals (71%) using ketamine followed this sequence: administration of sedatives, local anesthesia, primary repair, and imaging work-up. The most common sequence used for chloral hydrate (eight hospitals; 57%) was local anesthesia, administration of sedatives, imaging work-up, and primary repair. All hospitals that used ketamine and seven (50%) of those using chloral hydrate monitored oxygen saturation. Median operator satisfaction differed significantly between ketamine and chloral hydrate (4.0 [interquartile range, 4.0-4.0] vs. 3.0 [interquartile range, 3.0-4.0]; p <0.001). Conclusion The hospitals used various procedural sedation methods for children with facial lacerations. Guidelines that consider the patient's condition and drug characteristics are needed for safe and effective sedation.

• Korean Journal of Radiology
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• 제24권8호
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• pp.784-794
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• 2023

Objective: To determine whether dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) can be used to evaluate posterior cerebral circulation in pediatric patients with moyamoya disease (MMD) who underwent anterior revascularization. Materials and Methods: This study retrospectively included 73 patients with MMD who underwent DSC perfusion MRI (age, 12.2 ± 6.1 years) between January 2016 and December 2020, owing to recent-onset clinical symptoms during the follow-up period after completion of anterior revascularization. DSC perfusion images were analyzed using a dedicated software package (NordicICE; Nordic NeuroLab) for the middle cerebral artery (MCA), posterior cerebral artery (PCA), and posterior border zone between the two regions (PCA-MCA). Patients were divided into two groups; the PCA stenosis group included 30 patients with newly confirmed PCA involvement, while the no PCA stenosis group included 43 patients without PCA involvement. The relationship between DSC perfusion parameters and PCA stenosis, as well as the performance of the parameters in discriminating between groups, were analyzed. Results: In the PCA stenosis group, the mean follow-up duration was 5.3 years after anterior revascularization, and visual disturbances were a common symptom. Normalized cerebral blood volume was increased, and both the normalized time-topeak (nTTP) and mean transit time values were significantly delayed in the PCA stenosis group compared with those in the no PCA stenosis group in the PCA and PCA-MCA border zones. TTP_PCA (odds ratio [OR] = 6.745; 95% confidence interval [CI] = 2.665-17.074; P < 0.001) and CBV_PCA-MCA (OR = 1.567; 95% CI = 1.021-2.406; P = 0.040) were independently associated with PCA stenosis. TTP_PCA showed the highest receiver operating characteristic curve area in discriminating for PCA stenosis (0.895; 95% CI = 0.803-0.986). Conclusion: nTTP can be used to effectively diagnose PCA stenosis. Therefore, DSC perfusion MRI may be a valuable tool for monitoring PCA stenosis in patients with MMD.

• Clinical and Experimental Pediatrics
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• 제62권7호
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• pp.281-285
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• 2019

Purpose: To evaluate the association between elevated S100B levels with brain tissue damage seen in abnormalities of head magnetic resonance imaging (MRI; diffusion tensor imaging [DTI] sequence) in patients with status epilepticus (SE). Methods: An analytical observational study was conducted in children hospitalized at Dr Soetomo Hospital, Surabaya, from July to December 2016. The patients were divided into 2 groups: SE included all children with a history of SE; control included all children with febrile seizure. Blood samples of patients were drawn within 24 hours after admission. SE patients also underwent cranial MRI with additional DTI sequencing. The Mann-Whitney test and Spearman test were used for statistical analysis. Results: Fifty-three patients were enrolled the study. In the 24 children with SE who met the inclusion criteria, serum S100B and cranial MRI findings were assessed. Twenty-two children admitted with febrile seizures became the control group. Most patients were male (66.7%); the mean age was 35.8 months (standard deviation, 31.09). Mean S100B values of the SE group ($3.430{\pm}0.141{\mu}g/L$) and the control group ($2.998{\pm}0.572{\mu}g/L$) were significantly different (P<0.05). A significant difference was noted among each level of encephalopathy based on the cranial MRI results with serum S100B levels and the correlation was strongly positive with a coefficient value of 0.758 (P<0.001). Conclusion: In SE patients, there is an increase of serum S100B levels within 24 hours after seizure, which has a strong positive correlation with brain damage seen in head MRI and DTI.

• 대한방사선기술학회지:방사선기술과학
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• 제40권3호
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• pp.355-361
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• 2017

소아는 성인보다 장기의 방사선에 대한 감수성이 크고 성장 중이기 때문에 더 민감하다. 피폭으로 인한 부작용을 겪는 기대수명이 길기 때문에 피폭선량의 관리가 어른의 경우보다 중요하게 다뤄진다. 본 연구는 10세 팬텀을 사용하여 현재 우리나라에 권고되어 있는 5세 소아의 촬영기준과 입사표면선량의 적합성을 확인하고 추가적으로 제시된 촬영기준으로 장기흡수선량을 측정해보았다. 임상에서 사용 중인 5세와 10세의 촬영조건과 장기흡수선량, 입사표면선량을 비교하였다. 임상 5세 촬영조건이 권고촬영조건보다 약간 높으며 임상 10세 촬영조건은 많이 높게 나타났다. 또한 권고 촬영조건으로 ESD를 측정한 결과 임상 촬영조건의 ESD가 43% 높게 나타났으며 10세의 ESD는 5세의 권고 촬영조건의 ESD 보다 126% 증가를 나타냈다. 5세의 권고된 ESD와 임상 촬영조건에 의한 ESD를 비교한 결과 31.6%의 차이를 나타냈다. 5세의 권고 촬영조건과 임상 촬영조건에 의한 장기흡수선량은 큰 차이는 없으나 흉부와 골반검사에서는 차이가 컸다. 그러나 10세의 임상 촬영조건에 의한 장기흡수선량을 비교하면 월등한 차이가 있었음을 알 수 있었다. 따라서 소아의 권고 선량에 대한 더욱 세분화된 기준안이 연구되어야 할 것으로 사료된다.

• Advances in pediatric surgery
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• 제11권2호
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• pp.150-156
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• 2005

Failure of the urachus to regress completely results in anomalies that may be classified as patent urachus, urachal sinus, urachal cyst and bladder diverticula. The presenting symptoms of children with urachal anomalies are variable and uniform guidelines for diagnosis and treatment are lacking. The purpose of this study was to analyze our experience and develop conclusions regarding the presentation, diagnosis and treatment of urachal anomalies. We retrospectively analyzed the records of 32 patients who were admitted for urachal anomalies from March 1995 to February 2005. The age distribution of these patients at presentation ranged from 1 day to 14 years old (median age 1 month). There were 20 boys and 12 girls. The 32 cases comprised 13 cases of urachal sinus (40.6 %), 10 urachal cyst (31.3 %), and 9 patent urchus (28.1 %). In 30 patients ultrasonography was used for diagnosis and 2 patients with patent urachus were explored without using a diagnostic method. Twenty-three patients were confirmed by ultrasonography alone and 7 patients were examined using additional modalities, namely, computed tomography for 2 patients with an urachal cyst, magnetic resonance imaging for 1 patient with an urachal cyst, and fistulography for 3 patients with an urachal sinus. The presenting symptoms were umbilical discharge (14 patients), umbilical granuloma (8), abdominal pain and fever (3), fever (3), abdominal pain (2), and a low abdominal mass (2). Excision was performed in 29 patients, and 3 patients were conservatively managed. Urachal anomalies in children most frequently presented in neonates, and the most common complaint was umbilical discharge with infection. Urachal anomalies can be diagnosed by a physical examination and an appropriate radiographic test. Ultrasound was the most useful diagnostic method. Complete surgical excision of an urachal anomaly is recommended to avoid recurrence, and the rare development of carcinoma.

• Childhood Kidney Diseases
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• 제20권2호
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• pp.92-96
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• 2016

Henoch-$Sch{\ddot{o}}nlein$ purpura (HSP) is the most common vasculitis in children, mainly affecting the small vessels of the skin, joints, gastrointestinal tract, and kidneys. Although most cases of HSP resolve spontaneously without sequelae, serious nephrological and intestinal problems may occur in some cases. We experienced a case of HSP complicated by simultaneous intussusception and nephritis in a 14-year-old boy who developed a sudden abdominal pain and gross hematuria on the 11th day after onset of the disease. Imaging studies revealed intussusception that required emergency laparotomy. Despite treatment with steroid and angiotensin-converting enzyme inhibitors, nephritis and nephrosis progressed for 4 weeks, and renal biopsy was performed to confirm the diagnosis. Cyclosporin A therapy was started, and remission of proteinuria was achieved after 5 months. However, the nephritis recurred and worsened to end-stage renal failure during 15 years of follow-up.